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  <title>Document</title>
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    // function test() {
    //   let index = 9
    //   // while 循环会被return 跳出  同时函数执行完毕

    //   while (index > 5) {
    //     index--;
    //     console.log(index)
    //   }
    //   console.log('执行')
    // }
    // test()
    // return 也可以跳出for循环
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